Direct and Inverse Variation

Trina's paycheck earnings varies directly as the number of hours she works. If she works 19 hours and earns $187.15, what should she earn if she worked 40 hours?

$394

If y varies inversely with x and y = 6 when x = 9, what is y if x = 3

18

The gallons of water used to take a shower varies directly with the number of minutes in the shower. If an 8 minute shower uses 48 gallons of water, find the constant of variation.

6

If y varies directly with x, what is the constant of proportionality when y is 15 and x is 4.

60

The number of hours to paint a house varies inversely with the number of painters working. A 2400-square foot house can be painted in 27 hours by 6 painters. How many painters would need to work in order to paint the house in 18 hours?

9 painters

the variable k is the representation of _____________________ in the variation

Constant of Variation

Direct Variation

The relationship between two variable quantities that have a constant ratio.

Write the equation, "distance varies inversely to its rate"

d = k/r

In a variation, there have a _________________________ and _________________________ variables that shows a certain reletionships

dependent and independent

Inverse Variation

y=k/x

Which of the following represents indirect variation?

y=k/x

Which of the following represents direct variation?

y=kx